Laminated organic light-emitting device and display device

Abstract

The invention provides a laminated organic light-emitting device and a display device. The laminated organic light-emitting device comprises an anode, a first light-emitting unit, a second light-emitting unit and a cathode which are arranged in sequence, the first light-emitting unit comprises at least one A-type light-emitting subunit; the second light-emitting unit comprises at least one B-type light-emitting subunit; the hole mobility of the material of the electron barrier layer of at least one A-type light-emitting subunit is smaller than that of the material of the electron barrier layer of at least one B-type light-emitting subunit; and the hole mobility of the electron barrier layer material of at least one B-type light-emitting subunit is greater than or equal to 1.0 * 10 <-4 > cm < 2 >. V <-1 >. S <-1 >. Through the design and mutual compounding of electron barrier layer materials with different hole mobility in the light-emitting subunits, the hole transport effect is optimized, the working voltage of the device can be reduced, the current efficiency can be improved, and the service life can be prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of electroluminescence, and in particular relates to a laminated organic electroluminescent device and a display device. Background Art

[0002] Organic light-emitting diodes (OLEDs) are gradually gaining more and more attention due to their self-luminous properties, faster response speed, higher contrast, wider viewing angle, lower energy consumption, and thinner size. If a single-layer device structure is used in OLED devices, a higher operating voltage needs to be provided to achieve a certain luminous brightness, which results in excessive current passing through the device, adversely affecting the device's photoelectric performance and lifespan. A stacked organic electroluminescent device (hereinafter referred to as a stacked device) includes two or more light-emitting units, which are connected in series through a charge generation layer, so that the device's luminous brightness and current efficiency can be greatly improved to meet usage requirements.

[0003] Like single-layer organic electroluminescent devices, stacked devices also inevitably have the problem of life decay, and its life decay includes the life decay of each light-emitting unit. Among all the light-emitting units of the current stacked devices, except for the light-emitting layer materials that vary according to the color of the light-emitting unit, other organic functional layers basically use the same organic functional materials, and the hole / electron generation capacity of the charge generation layer is relatively weak, which makes the device operating voltage high and the life short. Compared with general OLED devices, the luminous efficiency of the entire stacked device is difficult to achieve an exponential increase. In recent years, the industry has been constantly exploring and trying to improve the performance and stability of stacked devices. Although the performance has been improved to a certain extent, the problem of high device operating voltage and severe life decay due to unbalanced carrier transmission has always existed.

[0004] Therefore, there is an urgent need in the art to develop a stacked organic electroluminescent device with higher performance. Summary of the invention

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a stacked organic electroluminescent device and a display device. By designing and compounding the electron blocking layers in each light-emitting unit, the operating voltage of the stacked organic electroluminescent device is effectively reduced, the luminous efficiency is improved, and the service life of the device is extended, thereby improving the display effect of the device.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a stacked organic electroluminescent device, the stacked organic electroluminescent device comprising an anode, a first light-emitting unit, a second light-emitting unit and a cathode arranged in sequence; the first light-emitting unit comprises at least one A-type light-emitting subunit, and the second light-emitting unit comprises at least one B-type light-emitting subunit; each of the A-type light-emitting subunits and each of the B-type light-emitting subunits independently comprises an electron blocking layer and a light-emitting layer; the hole mobility of the electron blocking layer material of at least one of the A-type light-emitting subunits is less than the hole mobility of the electron blocking layer material of at least one of the B-type light-emitting subunits; the hole mobility of the electron blocking layer material of at least one of the B-type light-emitting subunits is ≥1.0×10 - 4 cm 2 ·V -1 ·s -1 .

[0008] In the stacked organic electroluminescent device provided by the present invention, the second light-emitting unit close to the cathode includes at least one B-type light-emitting subunit, the first light-emitting unit close to the anode includes at least one A-type light-emitting subunit, and the electron blocking layer material in at least one of the B-type light-emitting subunits is a material with high hole mobility (hole mobility ≥1.0×10 - 4 cm 2 ·V -1 ·s -1 ), which has excellent hole transport performance; the hole mobility of the electron blocking layer material of at least one A-type light-emitting subunit is less than the hole mobility of the electron blocking layer material of at least one B-type light-emitting subunit, which has good hole transport performance and excellent hole injection performance. Different from the prior art in which all light-emitting units of the stacked device use the same electron blocking layer material, the present invention transfers more holes (such as holes in the charge generation layer) to the light-emitting layer through the design and mutual compounding of electron blocking layer materials with different hole mobilities in the light-emitting subunits, balances the injection and transport of holes, reduces hole accumulation, and improves the hole transport efficiency, thereby reducing the operating voltage of the stacked organic electroluminescent device, improving the luminous efficiency of the device, extending the service life, and comprehensively improving the display effect of the stacked organic electroluminescent device.

[0009] It is understandable that the stacked organic electroluminescent device of the present invention includes an anode, a first light-emitting unit, a second light-emitting unit and a cathode arranged in sequence according to a relative position relationship; the first light-emitting unit (relative to the second light-emitting unit) is close to the anode, and the second light-emitting unit (relative to the first light-emitting unit) is close to the cathode. Of course, the stacked organic electroluminescent device may also include other hierarchical structures (for example, other functional layers such as an electron injection layer may be optionally arranged between the second light-emitting unit and the cathode), and all stacked organic electroluminescent devices that satisfy the relative position relationship of "anode, first light-emitting unit, second light-emitting unit, cathode" belong to the protection scope of the present invention.

[0010] It should be noted that the first light-emitting unit of the present invention includes at least one A-type light-emitting subunit, that is, the number of A-type light-emitting subunits is ≥1, and can be 1, 2, 3, 4, 5 or 6, etc. The second light-emitting unit includes at least one B-type light-emitting subunit, that is, the number of B-type light-emitting subunits is ≥1, and can be 1, 2, 3, 4, 5 or 6, etc. The A-type light-emitting subunit and the B-type light-emitting subunit can both be referred to as "light-emitting subunits".

[0011] In the present invention, the hole mobility of the electron blocking layer material of at least one of the B-type luminescent subunits is ≥ 1.0×10 -4 cm 2 ·V -1 ·s -1 , for example, it can be 1.05×10 -4 cm 2 ·V -1 ·s -1 , 1.1×10 -4 cm 2 ·V -1 ·s -1 , 1.3×10 - 4 cm 2 ·V -1 ·s -1 , 1.5×10 -4 cm 2 ·V -1 ·s -1 , 1.7×10 -4 cm 2 ·V -1 ·s -1 , 1.9×10 -4 cm 2 ·V -1 ·s -1 , 2.0×10 -4 cm 2 ·V -1 ·s -1 , 2.2×10-4 cm 2 ·V -1 ·s -1 , 2.5×10 -4 cm 2 ·V -1 ·s -1 , 2.8×10 -4 cm 2 ·V -1 ·s -1 , 3.0×10 -4 cm 2 ·V -1 ·s -1 , 3.2×10 -4 cm 2 ·V -1 ·s -1 , 3.5×10 -4 cm 2 ·V -1 ·s -1 , 3.8×10 - 4 cm 2 ·V -1 ·s -1 , 4×10 -4 cm 2 ·V -1 ·s -1 4.2×10 -4 cm 2 ·V -1 ·s -1 , 4.5×10 -4 cm 2 ·V -1 ·s -1 , 4.8×10 -4 cm 2 ·V -1 ·s -1 , 5×10 -4 cm 2 ·V -1 ·s -1 or 5.2 × 10 -4 cm 2 ·V -1 ·s -1 wait.

[0012] Preferably, the hole mobility of the electron blocking layer material of at least one of the B-type light-emitting subunits is ≥ 2.0×10 -4 cm 2 ·V -1 ·s -1 .

[0013] Preferably, when the second light-emitting unit comprises at least two B-type light-emitting sub-units, the electron blocking layer material in each of the B-type light-emitting sub-units is the same or different.

[0014] Preferably, taking the direction from the anode to the cathode as the first direction, the hole mobility of the electron blocking layer material of the B-type light-emitting sub-unit in the second light-emitting unit increases along the first direction.

[0015] As a preferred technical solution of the present invention, the hole mobility of the electron blocking layer material of the B-type light-emitting subunit in the second light-emitting unit increases along the first direction, that is, the hole mobility of the electron blocking layer material of the light-emitting subunit closer to the cathode is greater.

[0016] Preferably, the hole mobility of the electron blocking layer material of the B-type light-emitting sub-unit in the second light-emitting unit increases uniformly along the first direction.

[0017] Optionally, when the second light-emitting unit includes at least two B-type light-emitting subunits, the electron blocking layer material in each of the B-type light-emitting subunits is the same, and the hole mobility of the electron blocking layer material of each B-type light-emitting subunit in the second light-emitting unit is equal.

[0018] Preferably, when the first light-emitting unit includes at least two A-type light-emitting sub-units, the electron blocking layer material in each of the A-type light-emitting sub-units is the same or different.

[0019] Optionally, when the first light-emitting unit includes at least two A-type light-emitting subunits, the electron blocking layer material in each of the A-type light-emitting subunits is the same, and the hole mobility of the electron blocking layer material of each A-type light-emitting subunit in the first light-emitting unit is equal.

[0020] More preferably, with the direction from the anode to the cathode as the first direction, the hole mobility of the electron blocking layer material of the light-emitting subunit between the anode and the cathode increases along the first direction. That is, as a preferred technical solution of the present invention, for all light-emitting subunits of the stacked organic electroluminescent device, the hole mobility of the electron blocking layer material increases along the first direction, that is, the closer the light-emitting subunit is to the cathode, the greater the hole mobility of the electron blocking layer material.

[0021] Preferably, each of the A-type light-emitting subunits independently further includes a hole transport layer, and the electron blocking layer is arranged between the hole transport layer and the light-emitting layer.

[0022] Preferably, the difference between the HOMO energy level of the hole transport layer and the HOMO energy level of the electron blocking layer of at least one of the A-type light-emitting subunits is δ1, 0<δ1<0.3eV, for example, δ1 can be 0.01eV, 0.03eV, 0.05eV, 0.08eV, 0.1eV, 0.12eV, 0.15eV, 0.18eV, 0.2eV, 0.22eV, 0.25eV or 0.28eV, etc., and further preferably 0<δ1<0.2eV.

[0023] Preferably, the difference between the HOMO energy level of the electron blocking layer of at least one of the A-type luminescent subunits and the HOMO energy level of the luminescent layer is δ2, 0<δ2<0.3eV, for example, δ2 can be 0.01eV, 0.03eV, 0.05eV, 0.08eV, 0.1eV, 0.12eV, 0.15eV, 0.18eV, 0.2eV, 0.22eV, 0.25eV or 0.28eV, etc., and further preferably 0<δ2<0.2eV.

[0024] Preferably, each of the B-type light-emitting subunits independently further includes a hole transport layer, and the electron blocking layer is arranged between the hole transport layer and the light-emitting layer.

[0025] Preferably, the difference between the HOMO energy level of the hole transport layer and the HOMO energy level of the electron blocking layer of at least one of the B-type light-emitting subunits is δ1', 0≤δ1'<0.3eV, for example, δ1' can be 0, 0.01eV, 0.03eV, 0.05eV, 0.08eV, 0.1eV, 0.12eV, 0.15eV, 0.18eV, 0.2eV, 0.22eV, 0.25eV or 0.28eV, etc., further preferably 0≤δ1'<0.2eV, and further preferably 0≤δ1'<0.1eV.

[0026] Preferably, the difference between the HOMO energy level of the electron blocking layer of at least one of the B-type luminescent subunits and the HOMO energy level of the luminescent layer is δ2', 0<δ2'<0.3eV, for example, δ2' can be 0.01eV, 0.03eV, 0.05eV, 0.08eV, 0.1eV, 0.12eV, 0.15eV, 0.18eV, 0.2eV, 0.22eV, 0.25eV or 0.28eV, etc., and further preferably 0<δ2'<0.2eV.

[0027] In the present invention, the "HOMO energy level of the light-emitting layer" refers to the HOMO energy level of the main material of the light-emitting layer. When the light-emitting layer contains at least two main materials, the HOMO energy level of the light-emitting layer refers to the HOMO energy level of the main material closest to the HOMO energy level of the electron blocking layer. Preferably, the HOMO energy levels of at least two main materials are both lower than the HOMO of the electron blocking layer.

[0028] Preferably, when the light-emitting layer comprises at least two host materials, the HOMO energy level of the light-emitting layer is the maximum value of the HOMO energy levels of the host materials.

[0029] Preferably, the difference between the LUMO energy level of the electron blocking layer of at least one of the A-type luminescent subunits and the LUMO energy level of the luminescent layer is δ3, δ3≥0, for example, δ3 can be 0.01eV, 0.02eV, 0.05eV, 0.08eV, 0.1eV, 0.12eV, 0.15eV, 0.18eV, 0.2eV, 0.22eV, 0.25eV or 0.28eV, etc., and δ3≥0.01eV is further preferred.

[0030] Preferably, the difference between the LUMO energy level of the electron blocking layer of at least one of the B-type luminescent subunits and the LUMO energy level of the luminescent layer is δ3', δ3'≥0, for example, δ3' can be 0, 0.01eV, 0.02eV, 0.05eV, 0.08eV, 0.1eV, 0.12eV, 0.15eV, 0.18eV, 0.2eV, 0.22eV, 0.25eV or 0.28eV, etc.

[0031] In the present invention, the "LUMO energy level of the light-emitting layer" refers to the LUMO energy level of the main material of the light-emitting layer. When the light-emitting layer contains at least two main materials, the LUMO energy level of the light-emitting layer refers to the LUMO energy level of the main material closest to the LUMO energy level of the electron blocking layer. Preferably, the LUMO energy levels of at least two main materials are both lower than the LUMO of the electron blocking layer.

[0032] Preferably, when the light-emitting layer comprises at least two host materials, the LUMO energy level of the light-emitting layer is the maximum value of the LUMO energy levels of the host materials.

[0033] Preferably, the HOMO energy level of the electron blocking layer of at least one of the A-type light-emitting subunits is -5.1eV to -5.4eV, for example, it can be -5.12eV, -5.15eV, -5.18eV, -5.2eV, -5.22eV, -5.25eV, -5.28eV, -5.3eV, -5.32eV, -5.35eV or -5.38eV, etc.

[0034] Preferably, the LUMO energy level of the electron blocking layer of at least one of the A-type light-emitting subunits is ≥ -1.70eV, for example, it can be -1.61eV, -1.62eV, -1.63eV, -1.64eV, -1.65eV, -1.66eV, -1.67eV, -1.68eV, -1.69eV or -1.70eV, etc.

[0035] Preferably, the hole mobility of the electron blocking layer of at least one of the A-type light-emitting subunits is less than 1.0×10 - 4 cm 2 ·V -1 ·s -1 , for example, it can be 1.0×10 -5 cm 2 ·V -1 ·s -1 , 1.5×10 -5 cm 2 ·V -1 ·s -1 , 2.0×10 -5 cm 2 ·V -1 ·s -1 , 2.5×10 -5 cm 2 ·V -1 ·s -1 , 3.0×10 -5 cm 2 ·V -1 ·s -1 , 3.5×10 -5 cm 2 ·V -1 ·s -1 4.0×10 -5 cm 2 ·V -1 ·s -1 , 4.5×10 -5 cm 2 ·V -1 ·s -1 5.0×10 -5 cm 2 ·V -1 ·s -1 , 5.5×10 -5 cm 2 ·V -1 ·s -1 , 6.0×10 -5 cm 2 ·V -1 ·s -1 , 6.5×10 -5 cm2 ·V -1 ·s -1 , 7.0×10 -5 cm 2 ·V -1 ·s -1 , 7.5×10 -5 cm 2 ·V -1 ·s -1 8.0×10 -5 cm 2 ·V -1 ·s -1 , 8.5×10 -5 cm 2 ·V -1 ·s -1 9.0×10 -5 cm 2 ·V -1 ·s -1 or 9.5×10 -5 cm 2 ·V -1 ·s -1 wait.

[0036] Preferably, the HOMO energy level of the electron blocking layer of at least one of the B-type light-emitting subunits is -5.1eV to -5.4eV, for example, it can be -5.12eV, -5.15eV, -5.18eV, -5.2eV, -5.22eV, -5.25eV, -5.28eV, -5.3eV, -5.32eV, -5.35eV or -5.38eV, etc.

[0037] Preferably, the LUMO energy level of the electron blocking layer of at least one of the B-type light-emitting subunits is ≥ -1.70eV, for example, it can be -1.61eV, -1.62eV, -1.63eV, -1.64eV, -1.65eV, -1.66eV, -1.67eV, -1.68eV, -1.69eV or -1.70eV, etc.

[0038] Preferably, when the first light-emitting unit includes at least two A-type light-emitting subunits, the electron blocking layer material in each of the A-type light-emitting subunits is the same or different; the hole transport layer material in each of the A-type light-emitting subunits is the same or different.

[0039] Preferably, the difference between the HOMO energy level of the hole transport layer of the A-type luminescent subunit and the HOMO energy level of the electron blocking layer is δ1; taking the direction from the cathode to the anode as the second direction, the δ1 of the A-type luminescent subunit in the first luminescent unit increases along the second direction.

[0040] As a preferred technical solution of the present invention, the difference between the HOMO energy level of the hole transport layer and the HOMO energy level of the electron blocking layer of the A-type light-emitting subunit in the first light-emitting unit increases along the second direction, that is, the closer to the anode, the greater the difference δ1 between the HOMO energy level of the hole transport layer and the HOMO energy level of the electron blocking layer in the light-emitting subunit.

[0041] Preferably, the manner in which δ1 of the A-type light-emitting subunit in the first light-emitting unit increases along the second direction is uniform increase.

[0042] Optionally, when the first light-emitting unit includes at least two A-type light-emitting subunits, the electron blocking layer material in each of the A-type light-emitting subunits is the same; the hole transport layer material in each of the A-type light-emitting subunits is the same, and the δ1 of each A-type light-emitting subunit in the first light-emitting unit is equal.

[0043] Preferably, when the second light-emitting unit includes at least two B-type light-emitting subunits, the electron blocking layer material in each of the B-type light-emitting subunits is the same or different; the hole transport layer material in each of the B-type light-emitting subunits is the same or different.

[0044] Optionally, the difference between the HOMO energy level of the hole transport layer and the HOMO energy level of the electron blocking layer of the B-type light-emitting subunit is δ1'. When the second light-emitting unit includes at least two B-type light-emitting subunits, the electron blocking layer material in each of the B-type light-emitting subunits is the same; the hole transport layer material in each of the B-type light-emitting subunits is the same, and the δ1' of each B-type light-emitting subunit in the second light-emitting unit is equal.

[0045] More preferably, with the direction from the cathode to the anode as the second direction, the difference between the HOMO energy level of the hole transport layer and the HOMO energy level of the electron blocking layer of the light-emitting subunit between the cathode and the anode increases along the second direction. That is, as a preferred technical solution of the present invention, for all light-emitting subunits of the stacked organic electroluminescent device, the difference between the HOMO energy level of the hole transport layer and the HOMO energy level of the electron blocking layer can increase along the second direction, that is, the closer the light-emitting subunit is to the anode, the greater the difference between the HOMO energy level of the hole transport layer and the HOMO energy level of the electron blocking layer.

[0046] As a preferred technical solution of the present invention, by designing and compounding electron blocking layer materials with different hole mobilities in the light-emitting subunit, and effectively matching the energy levels of adjacent layers (light-emitting layer and electron blocking layer, electron blocking layer and hole transport layer) in the same light-emitting subunit, more holes are further promoted to be transferred from the charge generation layer to the light-emitting layer, the injection and transport of holes are balanced, the hole accumulation is reduced, and the hole transport efficiency is improved, so that the stacked organic electroluminescent device has a lower operating voltage, a higher luminous efficiency and a longer service life.

[0047] It should be noted that the description of the difference in energy levels between layers in the present invention is for the same light-emitting subunit.

[0048] Preferably, the electron blocking layer material of at least one of the B-type light-emitting subunits has a structure as shown in Formula I:

[0049]

[0050] In Formula I, L1, L2, L3, and L4 are each independently selected from any one of a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group; when L1 is a single bond, it means that Ar1 is directly connected to the N atom through a single bond; the same applies to L2, L3, and L4, which are not described one by one.

[0051] In Formula I, Ar1, Ar2, and Ar3 are each independently selected from any one of a substituted or unsubstituted C6-C30 aryl group and a substituted or unsubstituted C3-C30 heteroaryl group.

[0052] In Formula I, R1, R2, R3, and R4 are each independently selected from any one of halogen, cyano, nitro, hydroxyl, amino, substituted or unsubstituted C1-C20 straight or branched alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 alkylsilyl, substituted or unsubstituted C6-C60 arylamino, substituted or unsubstituted C3-C60 heteroarylamino, substituted or unsubstituted C6-C60 aryl, and substituted or unsubstituted C3-C60 heteroaryl.

[0053] In formula I, R5 is selected from any one of a substituted or unsubstituted C1-C10 straight or branched alkyl group, and a substituted or unsubstituted C3-C20 cycloalkyl group.

[0054] In Formula I, n1, n2, n3, and n4 represent the number of substituents R1, R2, R3, and R4, respectively. n1 and n2 are each independently selected from integers of 0 to 3, such as 0, 1, 2, or 3. n3 is selected from integers of 0 to 4, such as 0, 1, 2, 3, or 4. n4 is selected from integers of 0 to 5, such as 0, 1, 2, 3, 4, or 5.

[0055] When n1≥2, multiple R1s are the same or different groups; the same applies to n2, n3 and n4, which will not be described one by one.

[0056] The substituents substituted in L1, L2, L3, L4, Ar1, Ar2, Ar3, R1, R2, R3, R4 and R5 are each independently selected from any one of halogen, C1-C20 straight or branched alkyl, C2-C20 alkenyl, C3-C20 cycloalkyl, C2-C20 heterocycloalkyl, C1-C10 alkoxy, carboxyl, nitro, cyano, amino, hydroxyl, mercapto, C1-C20 alkylsilyl, C1-C20 alkylamino, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryloxy, C3-C30 heteroaryloxy, C6-C60 aryl and C3-C60 heteroaryl. A combination of any one or at least two of them.

[0057] In the present invention, the "substituted or unsubstituted" group may be substituted with one substituent or with multiple substituents. When there are multiple substituents (at least 2), they may be the same or different substituents. When the same expressions are mentioned below, they have the same meaning. Unless otherwise specified, the selection ranges of substituents related to Formula I and Formula II are as shown above and will not be repeated one by one.

[0058] In the present invention, the halogen may be fluorine, chlorine, bromine or iodine. The following descriptions involving the same have the same meaning.

[0059] In the present invention, the expression of chemical elements, unless otherwise specified, includes the concept of isotopes with the same chemical properties. For example, hydrogen (H) includes 1 H (hydrogen), 2 H (deuterium, D), 3 H (tritium, T), etc.; carbon (C) includes 12 C. 13 C, etc.

[0060] In the present invention, unless otherwise specified, the heteroatom of the heteroaryl group is selected from N, O, S, P, B, Si or Se, preferably N, O or S.

[0061] In the present invention, the expression of a ring structure crossed by “—” indicates that the connection site is at any position on the ring structure that can form a bond.

[0062] In the present invention, "-*" and "*" both represent the connection site of a group.

[0063] In the present invention, the expression of Ca-Cb means that the number of carbon atoms in the group is ab. Unless otherwise specified, the number of carbon atoms does not include the number of carbon atoms in the substituent.

[0064] In the present invention, “each independently” means that when there are multiple subjects, they may be the same as or different from each other.

[0065] In the present invention, the C6-C30 may be C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26 or C28.

[0066] The C3-C30 can all be C3, C4, C5, C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26 or C28, etc.

[0067] The C1-C20 can all be C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18 or C19, etc.

[0068] The C3-C20 can all be C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18 or C19, etc.

[0069] The C6-C60 can all be C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, C30, C32, C34, C36, C38, C40, C42, C44, C46, ​​C48, C50, C52, C54, C56 or C58, etc.

[0070] The C3-C60 can all be C3, C4, C5, C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, C30, C32, C34, C36, C38, C40, C42, C44, C46, ​​C48, C50, C52, C54, C56 or C58, etc.

[0071] The C1-C10 can all be C2, C3, C4, C5, C6, C7, C8 or C9, etc.

[0072] The C2-C20 can all be C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18 or C19, etc.

[0073] In the present invention, the C6-C60 aryl group, preferably a C6-C30 aryl group, and more preferably a C6-C20 aryl group, includes a monocyclic aryl group and a condensed aryl group; the monocyclic aryl group means that the group contains at least one phenyl group, and when it contains at least two phenyl groups, the phenyl groups are connected by a single bond, and exemplary examples include but are not limited to: phenyl, biphenyl, terphenyl, etc.; the condensed aryl group means that the group contains at least two aromatic rings, and the aromatic rings share two adjacent aromatic rings. The carbon atoms of the groups are mutually fused, including, but not limited to, naphthyl, anthracenyl, phenanthrenyl, indenyl, fluorenyl and its derivatives (9,9-dimethylfluorenyl, 9,9-diethylfluorenyl, 9,9-dipropylfluorenyl, 9,9-dibutylfluorenyl, 9,9-dipentylfluorenyl, 9,9-dihexylfluorenyl, 9,9-diphenylfluorenyl, 9,9-dinaphthylfluorenyl, spirobifluorenyl, benzofluorenyl, etc.), fluoranthenyl, triphenylene, pyrenyl, perylene, Base or tetraphenyl etc.

[0074] The C3-C60 heteroaryl, preferably C3-C30 heteroaryl, further preferably C3-C20 heteroaryl, includes a monocyclic heteroaryl or a condensed ring heteroaryl. The monocyclic heteroaryl means that the molecule contains at least one heteroaryl. When the molecule contains a heteroaryl and other groups (such as aryl, heteroaryl, etc.), the heteroaryl and other groups are connected by a single bond, exemplarily including but not limited to: pyridyl, pyrimidyl, pyrazinyl, pyridazinyl, triazinyl, furanyl, thienyl, pyrrolyl, triazolyl, etc. The fused ring heteroaryl group means a group containing at least one aromatic heterocycle and one aromatic ring (aromatic heterocycle or aromatic ring) in the molecule, and the two share two adjacent atoms that are fused to each other, including, but not limited to, quinolyl, isoquinolyl, quinoxalinyl, quinazolinyl, benzimidazolyl, benzofuranyl, benzothiophenyl, isobenzofuranyl, isobenzothiophenyl, indolyl, dibenzofuranyl, dibenzothiophenyl, carbazolyl and its derivatives (N-phenylcarbazolyl, N-naphthylcarbazolyl, benzocarbazolyl, dibenzocarbazolyl, indolcarbazolyl, azacarbazolyl, etc.), acridinyl, phenothiazinyl, phenoxazinyl, hydrogenated acridinyl, benzofuranocarbazolyl, benzothiophenylcarbazolyl, azadibenzothiophenyl, azadibenzofuranyl, etc.

[0075] Specific examples of the C6-C30 arylene group include divalent groups obtained by removing a hydrogen atom from the above-mentioned aryl groups; specific examples of the C3-C30 heteroarylene group include divalent groups obtained by removing a hydrogen atom from the above-mentioned heteroaryl groups.

[0076] In the present invention, the C6-C30 aryloxy group is a monovalent group formed by connecting the above-mentioned aryl groups and O, and the C3-C30 heteroaryloxy group is a monovalent group formed by connecting the above-mentioned heteroaryl groups and O.

[0077] In the present invention, specific examples of the C6-C60 arylamino and C6-C30 arylamino groups are monovalent groups in which at least one hydrogen in -NH2 is replaced by the above aryl groups, including but not limited to phenylamino, methylphenylamino, naphthylamino, anthracenylamino, phenanthrenylamino, biphenylamino, etc. Specific examples of the C3-C60 heteroarylamino and C3-C30 heteroarylamino groups are monovalent groups in which at least one hydrogen in -NH2 is replaced by the above heteroaryl groups, including but not limited to pyridylamino, pyrimidinylamino, dibenzofuranylamino, etc.

[0078] The C1-C20 straight chain or branched alkyl group, preferably a C1-C10 straight chain or branched alkyl group, illustratively includes but is not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, 2-methylbutyl, n-pentyl, isopentyl, neopentyl, n-hexyl, neohexyl, 2-ethylhexyl, n-octyl, n-heptyl, n-nonyl, n-decyl, etc.

[0079] Specific examples of the C1-C20 alkoxy group and the C1-C10 alkoxy group include monovalent groups obtained by connecting the above-mentioned linear or branched alkyl groups to O.

[0080] A specific example of the C1-C20 alkylsilyl group is a monovalent group in which at least one hydrogen in -SiH3 is replaced by the above-mentioned straight-chain or branched alkyl group; a specific example of the C1-C20 alkylamino group is a monovalent group in which at least one hydrogen in -NH2 is replaced by the above-mentioned straight-chain or branched alkyl group.

[0081] The C3-C20 cycloalkyl, preferably C3-C10 cycloalkyl, includes monocycloalkyl or polycycloalkyl. Monocycloalkyl refers to an alkyl group containing a single cyclic structure, and polycycloalkyl refers to a structure composed of two or more cycloalkyl groups sharing one or more carbon atoms on the ring; exemplary examples include but are not limited to: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, etc.

[0082] Specific examples of the C2-C20 heterocycloalkyl group include monovalent groups formed by replacing at least one carbon atom in the above cycloalkyl group with a heteroatom (such as N, O or S, etc.), including but not limited to epoxy, oxetanyl, tetrahydrofuranyl, tetrahydrothiophenyl, tetrahydropyrrolyl, tetrahydropyranyl, piperidinyl, piperazinyl, dioxane, morpholinyl and the like.

[0083] The C2-C20 alkenyl, preferably C2-C10 alkenyl, contains at least one C=C, illustratively including but not limited to: vinyl, propenyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, butadienyl, pentadienyl and the like.

[0084] Specifically, the structure shown in Formula I is shown in any one of the following Formulas I-1, I-2, I-3, and I-4:

[0085]

[0086] Preferably, L1, L2, L3, and L4 are each independently selected from a single bond or a C6-C20 (e.g., C6, C7, C8, C9, C10, C12, C14, C16, or C18, etc.) arylene group, and a single bond or a phenylene group is more preferred.

[0087] Preferably, Ar1, Ar2, and Ar3 are each independently selected from any one of a substituted or unsubstituted C6-C20 (e.g., C6, C7, C8, C9, C10, C12, C14, C16, or C18, etc.) aryl group, and a substituted or unsubstituted C3-C20 (e.g., C3, C4, C5, C6, C7, C8, C9, C10, C12, C14, C16, or C18, etc.) heteroaryl group.

[0088] Preferably, Ar1, Ar2, Ar3 are each independently selected from any one or a combination of at least two of the following substituted or unsubstituted groups:

[0089] Wherein, -* represents the attachment site of the group.

[0090] R 11 represents mono-substituted to the maximum permissible substitution, for example, mono-substituted, di-substituted, tri-substituted, tetra-substituted, etc.; when R 11 When the number of R is ≥2, multiple R 11 are the same or different groups.

[0091] R 11The alkyl radicals are each independently selected from any one or a combination of at least two of halogen, C1-C20 straight or branched alkyl, C3-C20 cycloalkyl, C2-C20 heterocycloalkyl, C1-C10 alkoxy, carboxyl, nitro, cyano, amino, hydroxyl, mercapto, C1-C20 alkylsilyl, C1-C20 alkylamino, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryloxy, C3-C30 heteroaryloxy, C6-C30 aryl, C3-C30 heteroaryl, and more preferably C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, etc.) straight or branched alkyl. Preferably, the present invention is any one of C3-C10 (for example, C4, C5, C6, C7, C8, C9, etc.) cycloalkyl, C6-C20 (for example, C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) aryl, C3-C30 (for example, C4, C5, C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) heteroaryl, or a combination of at least two of them; more preferably, any one of C1-C6 straight-chain or branched-chain alkyl, cyclohexyl, phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, methylfluorenyl, phenylfluorenyl, or a combination of at least two of them.

[0092] X is selected from O, S, NR 12 or CR 13 R 14 Any one of .

[0093] R 12 , R 13 , R 14 Each is independently selected from any one of C1-C20 straight or branched alkyl, C2-C20 alkenyl, C3-C20 cycloalkyl, C6-C30 aryl or C3-C30 heteroaryl; the R 13 and R 14 Not connected or connected to form a ring through chemical bonds.

[0094] Preferably, the R 12 , R 13 , R 14 Each independently selected from any one of C1-C6 (e.g., C2, C3, C4, C5, etc.) straight or branched alkyl, phenyl, biphenyl, terphenyl or naphthyl; the R 13 and R 14 Not connected or connected by chemical bonds to form a spirobifluorenyl group.

[0095] More preferably, Ar1, Ar2, Ar3 are each independently selected from any one or a combination of two of the following substituted or unsubstituted groups:

[0096]

[0097]

[0098] Wherein, -* represents the attachment site of the group.

[0099] Preferably, R5 is selected from any one of C1-C6 (e.g., C2, C3, C4, C5, etc.) straight chain or branched alkyl, C3-C10 (e.g., C4, C5, C6, C7, C8, C9, etc.) cycloalkyl, and more preferably any one of methyl, ethyl, isopropyl, tert-butyl or cyclohexyl.

[0100] Preferably, R1, R2, R3, and R4 are each independently selected from any one of C1-C10 straight or branched alkyl, C3-C10 cycloalkyl, C6-C30 aryl, and C3-C30 heteroaryl, and more preferably any one of methyl, ethyl, propyl, tert-butyl, cyclopropyl, phenyl, naphthyl, anthracenyl, phenanthrenyl, biphenyl, and carbazole.

[0101] Preferably, n1, n2, n3, and n4 are each independently 0 or 1.

[0102] Preferably, the electron blocking layer material of at least one of the B-type light-emitting subunits is selected from any one or a combination of at least two of the compounds shown in the following P1-P624:

[0103]

[0104]

[0105]

[0106]

[0107]

[0108]

[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129] Preferably, the electron blocking layer material of at least one of the A-type light-emitting subunits has a structure as shown in Formula II:

[0130]

[0131] In Formula II, Ar S Each occurrence is independently selected from any one of a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group; when Ar S When it is a single bond, it means that the C atom and the N atom in the spirobifluorene structure are directly connected through a single bond.

[0132] In Formula II, Ar 4 ,Ar 5 Each occurrence is independently selected from any one of substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl; the Ar connected to the same N atom 4 and Ar 5 Not connected or connected via E.

[0133] It should be noted that Ar in Formula II S At most three times, multiple Ar S Same or different; Ar4 At most three times, Ar 5 At most three times, multiple Ar 4 Same or different, multiple Ar 5 Same or different.

[0134] E is selected from single bond, O, S, NR E1 or CR E2 R E3 Any one of .

[0135] R E1 , R E2 , R E3 Each is independently selected from any one of a substituted or unsubstituted C1-C20 straight or branched alkyl group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C6-C30 aryl group, and a substituted or unsubstituted C3-C30 heteroaryl group.

[0136] In Formula II, R 21 , R 22 , R 23 , R 24 Each is independently selected from any one of halogen, cyano, nitro, hydroxyl, amino, substituted or unsubstituted C1-C20 straight or branched alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 alkylsilyl, substituted or unsubstituted C6-C60 arylamino, substituted or unsubstituted C3-C60 heteroarylamino, substituted or unsubstituted C6-C60 aryl, and substituted or unsubstituted C3-C60 heteroaryl.

[0137] Ar S ,Ar 4 ,Ar 5 , R E1 , R E2 , R E3 , R 21 , R 22 , R 23 , R 24 The substituted substituents are each independently selected from any one of halogen, C1-C20 straight or branched alkyl, C2-C20 alkenyl, C3-C20 cycloalkyl, C2-C20 heterocycloalkyl, C1-C10 alkoxy, carboxyl, nitro, cyano, amino, hydroxyl, mercapto, C1-C20 alkylsilyl, C1-C20 alkylamino, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryloxy, C3-C30 heteroaryloxy, C6-C60 aryl, and C3-C60 heteroaryl. A combination of at least two.

[0138] In formula II, m, s, r, and t represent substituents R 21 , R 22 , R 23 , R 24 m is an integer selected from 0-2, for example, 0, 1 or 2. r, s, t are each independently selected from an integer selected from 0-4, for example, 0, 1, 2, 3 or 4. p, q are each independently 0 or 1. Moreover, s+q≤4, r+p≤4.

[0139] When m = 2, two R 21 are the same or different groups; when s≥2, multiple R 22 are the same or different groups; the same is true for r and t, which will not be described in detail.

[0140] Preferably, the Ar S Each occurrence is independently selected from a single bond or a C6-C20 (e.g., C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) arylene group, and a single bond or a phenylene group is more preferred.

[0141] Preferably, the Ar 4 ,Ar 5 Each occurrence is independently selected from any one of the following substituted or unsubstituted groups:

[0142] Wherein, -* represents the attachment site of the group.

[0143] Preferably, the Ar 4 and Ar 5 Do not connect or connect via single button.

[0144] Preferably, the electron blocking layer material of at least one of the A-type light-emitting subunits is a compound shown by M1-M11:

[0145]

[0146]

[0147] Preferably, when the total number of light-emitting sub-units in the first light-emitting unit and the second light-emitting unit is 2a+1, they are arranged in sequence according to the setting order, and the electron blocking layer material of the a+1th light-emitting sub-unit has a structure as shown in Formula I or Formula II, and further preferably has a structure as shown in Formula I; wherein a is an integer ≥1.

[0148] Preferably, the thickness of the electron blocking layer in at least one of the A-type light-emitting subunits and / or at least one of the B-type light-emitting subunits is independently 4-10 nm, for example, 5 nm, 6 nm, 7 nm, 8 nm or 9 nm, etc., more preferably 4-6 nm.

[0149] Preferably, the glass transition temperature (Tg) of the electron blocking layer material of at least one light-emitting sub-unit in the first light-emitting unit and the second light-emitting unit is ≥130°C, for example, it can be 132°C, 135°C, 138°C, 140°C, 142°C, 145°C, 148°C, 150°C, 152°C, 155°C, 158°C or 160°C, etc.

[0150] Preferably, at least one of the A-type light-emitting subunits and / or at least one of the B-type light-emitting subunits are independently selected from any one of a blue light-emitting subunit, a red light-emitting subunit or a green light-emitting subunit.

[0151] Preferably, a charge generation layer is arranged between any two adjacent light-emitting sub-units.

[0152] It can be understood that, in all the light-emitting sub-units located at the anode and the cathode, a charge generation layer is provided between any two adjacent light-emitting sub-units.

[0153] Preferably, the thickness of the charge generation layer is independently 5-15 nm, for example, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm or 14 nm, more preferably 9-11 nm.

[0154] Preferably, each of the A-type light-emitting subunits independently further includes any one of an electron transport layer, a hole blocking layer, and a hole injection layer, or a combination of at least two of them.

[0155] Preferably, each of the B-type light-emitting subunits independently further includes any one of an electron transport layer, a hole blocking layer, a hole transport layer, and a hole injection layer, or a combination of at least two thereof.

[0156] Preferably, each of the A-type light-emitting subunits and each of the B-type light-emitting subunits independently comprises an electron transport layer, a hole blocking layer, a light-emitting layer, an electron blocking layer, a hole transport layer and a hole injection layer which are arranged in sequence.

[0157] Preferably, an electron injection layer is further provided between the cathode and the second light-emitting unit.

[0158] In a preferred technical solution, a substrate is provided on the side of the anode facing away from the organic layer or the side of the cathode facing away from the organic layer. The substrate is a rigid substrate or a flexible substrate, which has excellent mechanical strength, thermal stability, waterproofness, and transparency; the rigid substrate exemplarily includes but is not limited to: a glass substrate, a Si substrate, etc., and the flexible substrate exemplarily includes but is not limited to: a polyvinyl alcohol (PVA) film, a polyimide (PI) film, a polyester (PET) film, etc. The substrate used as a display may be provided with a thin film transistor (TFT). The substrate of the present invention is preferably a rigid glass substrate.

[0159] In a preferred technical solution, the anode can be formed by sputtering or depositing a material used as the first electrode on a substrate. The anode is preferably a conductive compound, alloy, metal, and a mixture of such materials with a large work function; the metal oxide includes indium tin oxide (ITO), zinc oxide (ZnO), indium zinc oxide (IZO), tin oxide (SnO), etc., and the metal includes gold, silver, copper, aluminum, etc. with a relatively high work function; the anode in the present invention is preferably ITO.

[0160] The organic layer can be formed on the electrode by vacuum evaporation, spin coating, printing, etc., or by other methods, not limited to the above methods. In the preferred technical solution of the present invention, the device prepared by vacuum evaporation is described.

[0161] Preferably, the preparation method includes: cleaning, drying, pre-treating the substrate, entering the chamber, and vacuum depositing the hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, electron transport layer, electron injection layer, cathode, etc. of each light-emitting sub-unit in sequence.

[0162] In a preferred technical solution, the hole injection layer can be a single compound material or a combination of multiple compounds. For example, the hole injection layer can use one or more compounds of HT-1 to HT-51, or one or more compounds of HI-1 to HI-3; or one or more compounds of HT-1 to HT-51 can be doped with one or more compounds of HI-1 to HI-3.

[0163]

[0164] In a preferred technical solution, the material of the hole transport layer can be selected from, but not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylene ethylene, polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (Pani / PSS), aromatic amine derivatives; wherein the aromatic amine derivatives include compounds shown in HT-1 to HT-51 below; or any combination thereof.

[0165]

[0166]

[0167]

[0168] The light-emitting layer includes a light-emitting dye (i.e., dopant) that can emit light of different wavelength spectra, and may also include a host material (Host). The light-emitting layer may be a monochrome light-emitting layer that emits a single color such as red, green, and blue. A plurality of monochrome light-emitting layers of different colors may be arranged in a plane according to a pixel pattern, or may be stacked together to form a color light-emitting layer. When light-emitting layers of different colors are stacked together, they may be separated from each other or may be connected to each other. The light-emitting layer may also be a single color light-emitting layer that can simultaneously emit different colors such as red, green, and blue.

[0169] According to different technologies, the light-emitting layer material can be made of different materials such as fluorescent electroluminescent materials, phosphorescent electroluminescent materials, and thermally activated delayed fluorescent materials. In an OLED device, a single light-emitting technology can be used, or a combination of multiple different light-emitting technologies can be used. These different light-emitting materials classified by technology can emit light of the same color or different colors.

[0170] In one aspect of the present invention, the light-emitting layer adopts fluorescent electroluminescence technology. The fluorescent host material of the light-emitting layer can be selected from, but not limited to, one or more combinations of BFH-1 to BFH-17 listed below.

[0171]

[0172]

[0173] In one aspect of the present invention, the light-emitting layer adopts fluorescent electroluminescence technology. The fluorescent dopant (including blue light dye) of the light-emitting layer can be selected from, but not limited to, one or more combinations of BFD-1 to BFD-24 listed below.

[0174]

[0175]

[0176] In a preferred technical solution of the present invention, the light-emitting layer adopts phosphorescent luminescence technology, and the host material is selected from, but not limited to, one or more combinations of PH-1 to PH-85.

[0177]

[0178]

[0179]

[0180]

[0181]

[0182] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology, and the doping material (phosphorescent doping material, also known as guest material, dye) includes a green light material, which can be selected from, but not limited to, one or more combinations of GPD-1 to GPD-47 listed below.

[0183]

[0184] Where D is deuterium.

[0185] In a preferred technical solution, the light-emitting layer adopts phosphorescent electroluminescence technology, and the doping material of the light-emitting layer includes a red light material, which can be selected from, but not limited to, one or more combinations of RPD-1 to RPD-28 listed below.

[0186]

[0187] In a preferred technical solution, the light-emitting layer adopts phosphorescent electroluminescence technology, and the doping material of the light-emitting layer can be selected from, but not limited to, one or more combinations of YPD-1 to YPD-11 listed below.

[0188]

[0189] In a preferred technical solution, the material of the electron transport layer can be selected from, but not limited to, any one or a combination of at least two of the compounds ET-1 to ET-73 listed below.

[0190]

[0191]

[0192]

[0193]

[0194] In one aspect of the present invention, a hole blocking layer (HBL) is located between the electron transport layer and the light emitting layer. The hole blocking layer may be, but not limited to, one or more compounds of ET-1 to ET-73, or one or more compounds of PH-1 to PH-46; or a mixture of one or more compounds of ET-1 to ET-73 and one or more compounds of PH-1 to PH-46.

[0195] In one aspect of the present invention, the charge generation layer (CGL) material uses a compound having a structure as shown in Formula III:

[0196] R 31 -QR 32 Formula III;

[0197] In formula III, the bridging group Q is selected from one of the substituted or unsubstituted groups:

[0198]

[0199] Among them, the wavy line and the *wavy line represent the two connection sites of the group respectively.

[0200] In Formula III, R 31 , R 32 Each is independently selected from any one of substituted or unsubstituted C3-C60 heteroaryl groups, wherein the heteroaryl group contains at least one nitrogen atom.

[0201] Q, R 31 , R 32 The substituents in the substitution are each independently selected from any one or a combination of at least two of deuterium, tritium, cyano, halogen, C1-C10 alkyl, C3-C10 cycloalkyl, silicon, phosphino, C6-C30 aromatic amine, C6-C30 aryl, and C2-C30 heteroaryl; R 31 , R 32 The substituted substituents are independently connected to the connected heteroaromatic ring to form a ring or not.

[0202] In a preferred technical solution, the charge generation layer (CGL) material includes but is not limited to a combination of one or more of the following L1-L90:

[0203]

[0204]

[0205]

[0206]

[0207]

[0208]

[0209]

[0210]

[0211]

[0212] In a preferred technical solution, the material of the electron injection layer includes but is not limited to one or more combinations of the following: LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca, Mg or Yb.

[0213] In a preferred technical solution, the cathode can be made of metals or alloys such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), ytterbium (Yb), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), and any combination thereof. It can also be made of metals such as ITO, metal mixtures, oxides, etc. The cathode of the present invention is preferably a magnesium-silver (Mg-Ag) combination.

[0214] In a second aspect, the present invention provides a display device, comprising the stacked organic electroluminescent device as described in the first aspect.

[0215] Compared with the prior art, the present invention has the following beneficial effects:

[0216] The present invention provides a novel stacked organic electroluminescent device, which can transfer more holes from the charge generation layer to the light-emitting layer through the design and mutual compounding of electron blocking layer materials with different hole mobilities in the light-emitting sub-unit, balance the injection and transmission of holes, reduce hole accumulation, improve hole transmission efficiency, reduce the operating voltage of the device, improve the luminous efficiency, and extend the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0217] Figure 1 A schematic diagram of the structure of a stacked organic electroluminescent device provided in a specific embodiment of the present invention;

[0218] Among them, 1-glass substrate, 2-anode, 3-first hole injection layer, 4-first hole transport layer, 5-first electron blocking layer, 6-first light-emitting layer, 7-first hole blocking layer, 8-first electron transport layer, 9-charge generation layer, 10-second hole injection layer, 11-second hole transport layer, 12-second electron blocking layer, 13-second light-emitting layer, 14-second hole blocking layer, 15-second electron transport layer, 16-electron injection layer, 17-cathode, and 18-external power supply. DETAILED DESCRIPTION

[0219] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0220] In a specific embodiment, the electron blocking layer material of at least one of the A-type light-emitting subunits has a structure as shown in Formula II. The electron blocking layer material can be synthesized by methods disclosed in the prior art, for example, reference can be made to the contents disclosed in the prior art CN104114672A.

[0221] In a specific embodiment, the electron blocking layer material of at least one of the B-type luminescent subunits has a structure as shown in Formula I. The electron blocking layer material can be prepared by a synthesis method known in the art. A person skilled in the art can also prepare it by other existing technologies. Its representative synthesis route is as follows:

[0222] Wherein, L1, L2, L3, L4, Ar1, Ar2, Ar3, R1, R2, R3, R4, R5, n1, n2, n3, n4 have the same range as in Formula I; Hal1, Hal2, Hal3, Hal4 are each independently selected from halogen, preferably Cl or Br. The order of coupling reaction III and coupling reaction IV can be adjusted according to actual conditions.

[0223] Preferably, the coupling reaction I, coupling reaction II, coupling reaction III and coupling reaction IV are carried out in the presence of a palladium catalyst.

[0224] Preferably, the palladium catalyst includes any one of tri(dibenzylideneacetone)dipalladium Pd2(dba)3 and tetrakistriphenylphosphine palladium Pd(PPh3)4; preferably, the catalyst for the coupling reaction I is Pd(PPh3)4; the catalyst for the coupling reaction II, coupling reaction III and coupling reaction IV is Pd2(dba)3.

[0225] Preferably, the coupling reaction I is carried out in the presence of Pd(PPh3)4 and an alkaline substance (eg, potassium carbonate).

[0226] Preferably, the coupling reaction II is carried out in the presence of Pd2(dba)3, an organic phosphine ligand (eg, 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl, ie, Sphos) and a basic substance (eg, potassium phosphate).

[0227] Preferably, the coupling reaction III is carried out in the presence of Pd2(dba)3, a ligand (eg, 1,3-bis(2,6-diisopropylphenyl)imidazolium chloride, ie, IPr·HCl) and an alkaline substance (eg, sodium tert-butoxide).

[0228] Preferably, the coupling reaction II is carried out in the presence of Pd2(dba)3, an organic phosphine ligand (eg, tri-tert-butylphosphine, ie, (t-Bu)3P) and an alkaline substance (eg, sodium tert-butoxide).

[0229] Preferably, the reducing agent of the reduction reaction includes hydrazine hydrate (N2H4·H2O); the reduction reaction is preferably carried out under the catalysis of a palladium-carbon catalyst.

[0230] The specific preparation method of the electron blocking layer material having the structure shown in Formula I of the present invention will be described in detail below with multiple preparation examples, but the preparation method of the present invention is not limited to these preparation examples. The compounds not mentioned in the present invention are all raw materials obtained through commercial channels, or are prepared by these raw materials according to known methods. The solvents and reagents used in the present invention can all be purchased from the chemical product market.

[0231] The structural analysis (m / z data) of the compounds of the present invention was obtained by using a ZAB-HS mass spectrometer (manufactured by Micromass, UK).

[0232] Preparation Example 1: Preparation of Compound P2

[0233]

[0234] (1) Synthesis of P2-1

[0235] In a 1000mL single-mouth bottle, add 20.0g 2,3-dichloronitrobenzene, 15.2g phenylboric acid, 1.2g tetrakistriphenylphosphine palladium Pd(PPh3)4, 28.8g potassium carbonate, 300mL 1,4-dioxane and 100mL water, evacuate and replace nitrogen 3 times, and heat the reaction to 100℃ for 5h. After the reaction is complete, stop the reaction. Cool to room temperature, separate the reaction solution, filter the organic phase through a silica gel column twice, concentrate the organic phase, add methanol and reflux and stir for 1h, filter to obtain a light yellow powder P2-1, and then recrystallize from ethyl acetate to obtain 19.8g of pure product.

[0236] Calculated m / z value: 233.02; measured m / z value: 233.03.

[0237] (2) Synthesis of P2-2

[0238] In a 1000mL single-mouth bottle, add 19.8g P2-1, 12.4g phenylboric acid, 0.8g tris(dibenzylideneacetone)dipalladium Pd2(dba)3, 0.7g 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl Sphos, 36.0g anhydrous potassium phosphate, 300mL 1,4-dioxane and 30mL water, vacuum and replace nitrogen 3 times, and heat the reaction to 100℃ for 5h. After the reaction is complete, stop the reaction. Cool to room temperature, separate the reaction solution, filter the organic phase through a silica gel column twice, concentrate the organic phase, add methanol and reflux and stir for 1h, filter to obtain a light yellow powder P2-2, and then recrystallize from ethyl acetate to obtain 17.6g of pure product.

[0239] Calculated m / z value: 275.09; measured m / z value: 275.07.

[0240] (3) Synthesis of P2-3

[0241] In a 1000mL single-mouth bottle, add 17.6g P2-2, 3.5mL hydrazine hydrate, 0.5g palladium carbon catalyst (i.e. Pd / C) and 300mL ethanol, evacuate and replace nitrogen 3 times, and heat the reaction to 90°C for 5h. After the reaction is complete, stop the reaction. Cool to room temperature, separate the reaction solution, filter the organic phase through a silica gel column twice, concentrate the organic phase, add methanol and reflux and stir for 1h, filter to obtain white powder P2-3, and then recrystallize from ethyl acetate to obtain 13.9g of pure product.

[0242] Calculated m / z value: 245.12; measured m / z value: 245.11.

[0243] (4) Synthesis of P2-4

[0244] In a 1000mL single-mouth bottle, add 13.9g P2-3, 18.9g 2-bromo-9-methyl-9-phenylfluorene, 0.5g Pd2(dba)3, 0.5g 1,3-bis(2,6-diisopropylphenyl)imidazolium chloride IPr·HCl, 16.3g sodium tert-butoxide NaOBu-t, 300mL toluene, vacuum and replace nitrogen 3 times, and heat the reaction to 90℃ for 8h. After the reaction is complete, stop the reaction and cool to room temperature. The organic phase is filtered through a silica gel column, concentrated, ethanol is added and refluxed for 2h, cooled and filtered to obtain a yellow powder, and then recrystallized twice from toluene / ethanol to obtain 20.1g of pure product.

[0245] Calculated m / z value: 499.25; measured m / z value: 499.23.

[0246] (5) Synthesis of target product P2

[0247] In a 1000mL single-mouth bottle, add 20.1g P2-4, 11.3g 4-bromobiphenyl, 0.4g Pd2(dba)3, 0.3mL tri-tert-butylphosphine (t-Bu)3P, 11.6g NaOBu-t, 300mL toluene, vacuum and replace nitrogen 3 times, and heat the reaction to 110℃ for 12h. After the reaction is complete, stop the reaction and cool to room temperature. Filter the organic phase through a silica gel column, concentrate the organic phase, add ethanol and reflux and stir for 2h, cool and filter to obtain a yellow powder, and then recrystallize it twice with toluene / ethanol to obtain 10.3g of pure product.

[0248] Calculated m / z value: 651.31; measured m / z value: 651.32.

[0249] Preparation Example 2: Preparation of Compound P14

[0250]

[0251] The synthesis method of compound P14 is similar to that of compound P2, except that 4-bromobiphenyl in step (5) of Preparation Example 1 is replaced with an equimolar equivalent of 9,9-dimethyl-2-bromofluorene, and other raw materials, amounts and preparation processes are the same as those in Preparation Example 1 to obtain compound P14.

[0252] Calculated m / z value: 691.34; measured m / z value: 691.33.

[0253] Example 1

[0254] A stacked organic electroluminescent device comprises an anode, a cathode and two light-emitting subunits arranged between the anode and the cathode, and its structural schematic diagram is shown as follows Figure 1 As shown, it specifically includes a glass substrate 1, an anode 2 (ITO), a first hole injection layer 3, a first hole transport layer 4, a first electron blocking layer 5, a first light-emitting layer 6, a first hole blocking layer 7, a first electron transport layer 8, a charge generation layer 9, a second hole injection layer 10, a second hole transport layer 11, a second electron blocking layer 12, a second light-emitting layer 13, a second hole blocking layer 14, a second electron transport layer 15, an electron injection layer 16, and a cathode 17 (Mg-Ag electrode) which are stacked in sequence; the anode 2 and the cathode 17 are connected to an external power supply 18.

[0255] The preparation method of the stacked organic electroluminescent device is as follows:

[0256] (1) a glass substrate coated with an ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone / ethanol mixed solvent, baked in a clean environment until the water was completely removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam;

[0257] (2) Vacuum evaporation to prepare the first light-emitting subunit:

[0258] The glass substrate with the anode is placed in a vacuum chamber and evacuated to a vacuum of less than 1×10 -5 Pa, on the above-mentioned anode layer film, 10 nm of a mixture of compounds HT-4:HI-3 (97 / 3, w / w) was vacuum-deposited in sequence as the first hole injection layer, 25 nm of a mixture of compounds HT-4 was used as the first hole transport layer, 6 nm of a mixture of compounds M1 was used as the first electron blocking layer, 40 nm of a ternary mixture of compounds PH-61:PH-3:GPD-12 (100:100:20, w / w / w) was used as the first light-emitting layer, 5 nm of a mixture of compounds ET-23 was used as the first hole blocking layer, and 20 nm of a mixture of compounds ET-69:ET-57 (50 / 50, w / w) was used as the first electron transport layer to obtain the first light-emitting subunit;

[0259] (3) Vacuum evaporating 10 nm of compound L1 on the first electron transport layer as a charge generation layer;

[0260] (4) Vacuum evaporation to prepare the second light-emitting subunit:

[0261] On the charge generation layer, 10 nm of a mixture of compounds HT-4:HI-3 (97 / 3, w / w) was sequentially vacuum-deposited as a second hole injection layer, 25 nm of a mixture of compounds HT-4 was used as a second hole transport layer, 6 nm of a mixture of compounds P57 was used as a second electron blocking layer, 40 nm of a ternary mixture of compounds PH-61:PH-3:GPD-12 (100:100:20, w / w / w) was used as a second light-emitting layer, 5 nm of a mixture of compounds ET-23 was used as a second hole blocking layer, and 20 nm of a mixture of compounds ET-69:ET-57 (50 / 50, w / w) was used as a second electron transport layer to obtain a second light-emitting subunit;

[0262] (5) Vacuum evaporate 1 nm of Yb on the second light-emitting subunit as an electron injection layer;

[0263] (6) Vacuum evaporation of 13 nm of Mg:Ag (1:9, mass ratio) was performed on the electron injection layer as a cathode to obtain the stacked organic electroluminescent device.

[0264] Examples 2-19, Comparative Examples 1-17

[0265] A stacked organic electroluminescent device, which differs from Example 1 only in that the materials of the electron blocking layer are the compounds shown in Table 2, and the other layers, thicknesses and materials in each light-emitting subunit are the same as those of the light-emitting subunit in Example 1; for a stacked organic electroluminescent device with a number of light-emitting subunits greater than 2, the preparation method thereof differs from Example 1 in that steps (3) and (4) are repeated until all light-emitting subunits are prepared, and then 1 nm of Yb is vacuum evaporated on the electron transport layer of the last light-emitting subunit as an electron injection layer, and then 13 nm of Mg:Ag (1:9) is vacuum evaporated on the electron injection layer as a cathode.

[0266] Among them, the second electron blocking layer material in Comparative Example 8 is compound N1, and the structural formula is as follows:

[0267]

[0268] The organic materials used in the specific implementation of the present invention are tested, and the specific method is as follows:

[0269] (1) Hole mobility

[0270] The glass substrate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone / ethanol mixed solvent, baked in a clean environment until the water was completely removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam. The glass substrate with the anode was placed in a vacuum chamber and evacuated to less than 1×10 -5 Pa, 10nm of compound HT-4:HI-3 (97 / 3, w / w) mixture, 150nm of the material to be tested, 3nm HI-3, and 13nm of Mg:Ag (1:9) were vacuum-deposited on the above anode layer to make a single carrier device. The IV characteristics of the single carrier device were tested using a digital source meter and a brightness meter, and the carrier mobility under an electric field strength of 0.14mV / cm was calculated using the SCLC (space charge limited current) method for data accumulation and comparison.

[0271] (2) LUMO energy level and HOMO energy level

[0272] Cyclic voltammetry was performed on the material to be tested using an electrochemical workstation. The workstation used a three-electrode system, with a platinum electrode as the working electrode, a platinum wire electrode as the counter electrode, and an Ag wire electrode as the reference electrode. 0.5 g of the sample to be tested was dissolved in 5 mL of ultra-dry tetrahydrofuran, tetra-n-butylammonium perchlorate was used as the electrolyte salt, and the test sample was protected by nitrogen. The voltage range was -2 V to 2 V, the scanning speed was 100 mV / s, and the number of scanning circles was 2 circles. On the CV curve, the peak value, i.e., the oxidation potential E ox and reduction potential E red, according to the same settings as above, test the oxidation potential E of ferrocene Fe . Calculated HOMO = -((E ox -E Fe )+4.8), LUMO=-((E red -E Fe )+4.8).

[0273] The test results are shown in Table 1:

[0274] Table 1

[0275] Material No. <![CDATA[Hole mobility (cm 2 ·V -1 ·s -1 )]]> HOMO(eV) LUMO(eV) M1 <![CDATA[2.31×10 -5 ]]> -5.24 -1.66 M3 <![CDATA[3.12×10 -5 ]]> -5.23 -1.61 N1 <![CDATA[7.35×10 -5 ]]> -5.24 -1.69 P57 <![CDATA[3.45×10 -4 ]]> -5.21 -1.62 P2 <![CDATA[2.40×10 -4 ]]> -5.22 -1.63 P47 <![CDATA[2.21×10 -4 ]]> -5.21 -1.63 P14 <![CDATA[2.13×10 -4 ]]> -5.23 -1.64 P53 <![CDATA[1.08×10 -4 ]]> -5.23 -1.6 P105 <![CDATA[2.24×10 -4 ]]> -5.23 -1.62 P183 <![CDATA[2.41×10 -4 ]]> -5.22 -1.63 P234 <![CDATA[2.38×10 -4 ]]> -5.21 -1.62 P368 <![CDATA[1.12×10 -4 ]]> -5.23 -1.6 P410 <![CDATA[1.04×10 -4 ]]> -5.23 -1.6 P543 <![CDATA[3.01×10 -4 ]]> -5.23 -1.61 P588 <![CDATA[2.58×10 -4 ]]> -5.23 -1.6 P605 <![CDATA[3.89×10 -4 ]]> -5.22 -1.59 P623 <![CDATA[2.96×10 -4 ]]> -5.22 -1.62 HT-4 / -5.21 -1.7 PH-61 / -5.38 -1.7 PH-3 / -5.89 -2.68

[0276] The performance test of the stacked organic electroluminescent devices provided in Examples 1-19 and Comparative Examples 1-17 was carried out in the following manner:

[0277] (1) At the same current density, use a digital source meter and a brightness meter to measure the driving voltage and current efficiency of each stacked organic electroluminescent device. Specifically, the voltage is increased at a rate of 0.1 V per second, and the current density of the stacked organic electroluminescent device is measured when it reaches 100 A / m 2 The voltage at this time is the working voltage, and the brightness at this time is measured at the same time. The ratio of brightness to current density is the current efficiency.

[0278] (2) The test method for LT97 life is as follows: at 200A / m 2 Under constant current density, measure the time required for the brightness to decay to 97% of the initial brightness;

[0279] For the stacked organic electroluminescent device with two light-emitting subunits, the test values ​​of the operating voltage, current efficiency, and LT97 life of Comparative Example 1 are recorded as 1, and the operating voltage, current efficiency, and LT97 life of each embodiment and other comparative examples are the ratios of their respective test values ​​to the test values ​​of Comparative Example 1 (relative voltage, relative current efficiency); for the stacked organic electroluminescent device with three light-emitting subunits, the test values ​​of the operating voltage, current efficiency, and LT97 life of Comparative Example 9 are recorded as 1, and the operating voltage, current efficiency, and LT97 life of each embodiment and other comparative examples are the ratios of their respective test values ​​to the test values ​​of Comparative Example 9. For a stacked organic electroluminescent device having four light-emitting subunits, the test values ​​of the operating voltage, current efficiency, and LT97 life of Comparative Example 12 are recorded as 1, and the operating voltage, current efficiency, and LT97 life of each embodiment and other comparative examples are the ratios of their respective test values ​​to the test values ​​of Comparative Example 12; for a stacked organic electroluminescent device having five light-emitting subunits, the test values ​​of the operating voltage, current efficiency, and LT97 life of Comparative Example 15 are recorded as 1, and the operating voltage, current efficiency, and LT97 life of each embodiment and other comparative examples are the ratios of their respective test values ​​to the test values ​​of Comparative Example 15;

[0280] The test results are shown in Table 2; "EBL" in Table 2 means electron blocking layer; taking Comparative Example 1 as an example, " / " represents that it has 2 light-emitting sub-units, that is, there is no third EBL, fourth EBL and fifth EBL; the same applies to other " / ".

[0281] Table 2

[0282]

[0283]

[0284] Combining the data in Table 1 and Table 2, it can be seen that in the stacked organic electroluminescent device provided by the present invention, by setting the hole mobility of the electron blocking layer material in at least one luminescent subunit close to the cathode to be greater than the hole mobility of the electron blocking layer material in at least one luminescent subunit close to the anode, and making the hole mobility of the electron blocking layer material in at least one luminescent subunit close to the cathode be ≥1.0×10 -4 cm 2 ·V -1 ·s -1 The strong transport material can exert a performance better than that of a single electron blocking layer material through the design and mutual compounding of electron blocking layer materials with different hole mobilities in the light-emitting sub-unit, so that more holes are transferred from the charge generation layer to the light-emitting layer, balancing the injection and transport of holes, reducing hole accumulation, and improving the hole transport efficiency, thereby effectively reducing the operating voltage of the device, improving the current efficiency, and extending the service life.

[0285] The applicant declares that the present invention uses the above embodiments to illustrate the stacked organic electroluminescent device and display device of the present invention, but the present invention is not limited to the above process steps, that is, it does not mean that the present invention must rely on the above process steps to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A stacked organic electroluminescent device, characterized in that: The stacked organic electroluminescent device comprises an anode, a first light-emitting unit, a second light-emitting unit and a cathode which are arranged in sequence; The first light-emitting unit includes at least one A-type light-emitting subunit, and the second light-emitting unit includes at least one B-type light-emitting subunit; each of the A-type light-emitting subunits and each of the B-type light-emitting subunits independently includes an electron blocking layer and a light-emitting layer; The hole mobility of the electron blocking layer material of at least one of the A-type light-emitting subunits is less than the hole mobility of the electron blocking layer material of at least one of the B-type light-emitting subunits; The hole mobility of the electron blocking layer material of at least one of the B-type light-emitting subunits is ≥ 1.0×10 -4 cm 2 ·V -1 ·s -1 .

2. The stacked organic electroluminescent device according to claim 1, characterized in that: When the second light-emitting unit includes at least two B-type light-emitting subunits, the electron blocking layer materials in each of the B-type light-emitting subunits are the same or different; Preferably, taking the direction from the anode to the cathode as the first direction, the hole mobility of the electron blocking layer material of the B-type light-emitting sub-unit in the second light-emitting unit increases along the first direction.

3. The stacked organic electroluminescent device according to claim 1, characterized in that: Each of the A-type light-emitting subunits independently further includes a hole transport layer, and the electron blocking layer is arranged between the hole transport layer and the light-emitting layer; Preferably, the difference between the HOMO energy level of the hole transport layer and the HOMO energy level of the electron blocking layer of at least one of the A-type luminescent subunits is δ1, 0<δ1<0.3eV, and more preferably 0<δ1<0.2eV; Preferably, the difference between the HOMO energy level of the electron blocking layer of at least one of the A-type luminescent subunits and the HOMO energy level of the luminescent layer is δ2, 0<δ2<0.3eV, and more preferably 0<δ2<0.2eV; Preferably, the difference between the LUMO energy level of the electron blocking layer of at least one of the A-type luminescent subunits and the LUMO energy level of the luminescent layer is δ3, δ3≥0, and more preferably δ3≥0.01 eV.

4. The stacked organic electroluminescent device according to claim 3, characterized in that: The HOMO energy level of the electron blocking layer of at least one of the A-type light-emitting subunits is -5.1 eV to -5.4 eV; Preferably, the LUMO energy level of the electron blocking layer of at least one of the A-type light-emitting subunits is ≥ -1.70 eV.

5. The stacked organic electroluminescent device according to claim 3, characterized in that: When the first light-emitting unit includes at least two A-type light-emitting subunits, the electron blocking layer materials in each of the A-type light-emitting subunits are the same or different; the hole transport layer materials in each of the A-type light-emitting subunits are the same or different; Preferably, the difference between the HOMO energy level of the hole transport layer and the HOMO energy level of the electron blocking layer of the A-type light-emitting subunit is δ1; taking the direction from the cathode to the anode as the second direction, the δ1 of the A-type light-emitting subunit in the first light-emitting unit increases along the second direction.

6. The stacked organic electroluminescent device according to claim 1, characterized in that: The electron blocking layer material of at least one of the B-type light-emitting subunits has a structure as shown in Formula I: Wherein, L1, L2, L3, and L4 are each independently selected from any one of a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group; Ar1, Ar2, Ar3 are each independently selected from any one of a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group; R1, R2, R3, and R4 are each independently selected from any one of halogen, cyano, nitro, hydroxyl, amino, substituted or unsubstituted C1-C20 straight or branched alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 alkylsilyl, substituted or unsubstituted C6-C60 arylamino, substituted or unsubstituted C3-C60 heteroarylamino, substituted or unsubstituted C6-C60 aryl, and substituted or unsubstituted C3-C60 heteroaryl; R5 is selected from any one of substituted or unsubstituted C1-C10 straight or branched alkyl, substituted or unsubstituted C3-C20 cycloalkyl; The substituents substituted in L1, L2, L3, L4, Ar1, Ar2, Ar3, R1, R2, R3, R4 and R5 are each independently selected from any one or a combination of at least two of halogen, C1-C20 straight or branched alkyl, C2-C20 alkenyl, C3-C20 cycloalkyl, C2-C20 heterocycloalkyl, C1-C10 alkoxy, carboxyl, nitro, cyano, amino, hydroxyl, mercapto, C1-C20 alkylsilyl, C1-C20 alkylamino, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryloxy, C3-C30 heteroaryloxy, C6-C60 aryl and C3-C60 heteroaryl; n1 and n2 are each independently selected from integers of 0-3, n3 is selected from integers of 0-4, and n4 is selected from integers of 0-5.

7. The stacked organic electroluminescent device according to claim 6, characterized in that: The L1, L2, L3, L4 are each independently selected from a single bond or a C6-C20 arylene group, preferably a single bond or a phenylene group; and / or, Ar1, Ar2, and Ar3 are each independently selected from any one of a substituted or unsubstituted C6-C20 aryl group and a substituted or unsubstituted C3-C20 heteroaryl group; Preferably, Ar1, Ar2, Ar3 are each independently selected from any one or a combination of at least two of the following substituted or unsubstituted groups: Wherein, -* represents the attachment site of the group; R 11 Indicates single substitution to the maximum allowable substitution, R 11 Each is independently selected from any one or a combination of at least two of halogen, C1-C20 straight or branched alkyl, C3-C20 cycloalkyl, C2-C20 heterocycloalkyl, C1-C10 alkoxy, carboxyl, nitro, cyano, amino, hydroxyl, mercapto, C1-C20 alkylsilyl, C1-C20 alkylamino, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryloxy, C3-C30 heteroaryloxy, C6-C30 aryl, and C3-C30 heteroaryl; X is selected from O, S, NR 12 or CR 13 R 14 Any of the following; R 12 , R 13 , R 14 Each is independently selected from any one of C1-C20 straight or branched alkyl, C2-C20 alkenyl, C3-C20 cycloalkyl, C6-C30 aryl or C3-C30 heteroaryl; the R 13 and R 14 Not connected or connected into rings by chemical bonds; More preferably, Ar1, Ar2, Ar3 are each independently selected from any one or a combination of two of the following substituted or unsubstituted groups: Wherein, -* represents the attachment site of the group; and / or, The R5 is selected from any one of a C1-C6 straight chain or branched chain alkyl group, a C3-C10 cycloalkyl group, and preferably any one of a methyl group, an ethyl group, an isopropyl group, a tert-butyl group or a cyclohexyl group.

8. The stacked organic electroluminescent device according to any one of claims 1 to 7, characterized in that: The electron blocking layer material of at least one of the A-type light-emitting subunits has a structure as shown in Formula II: Among them, Ar S Each occurrence is independently selected from any one of a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group; Ar 4 ,Ar 5 Each occurrence is independently selected from any one of substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl; the Ar connected to the same N atom 4 and Ar 5 Not connected or connected via E; E is selected from single bond, O, S, NR E1 or CR E2 R E3 Any of the following; R E1 , R E2 , R E3 Each is independently selected from any one of a substituted or unsubstituted C1-C20 straight or branched alkyl group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C6-C30 aryl group, and a substituted or unsubstituted C3-C30 heteroaryl group; R 21 , R 22 , R 23 , R 24 Each is independently selected from any one of halogen, cyano, nitro, hydroxyl, amino, substituted or unsubstituted C1-C20 straight or branched alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 alkylsilyl, substituted or unsubstituted C6-C60 arylamino, substituted or unsubstituted C3-C60 heteroarylamino, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl; Ar S ,Ar 4 ,Ar 5 , R E1 , R E2 , R E3 , R 21 , R 22 , R 23 , R 24 The substituents substituted in the above-mentioned substituents are each independently selected from any one or a combination of at least two of halogen, C1-C20 straight or branched alkyl, C2-C20 alkenyl, C3-C20 cycloalkyl, C2-C20 heterocycloalkyl, C1-C10 alkoxy, carboxyl, nitro, cyano, amino, hydroxyl, mercapto, C1-C20 alkylsilyl, C1-C20 alkylamino, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryloxy, C3-C30 heteroaryloxy, C6-C60 aryl, and C3-C60 heteroaryl; m is an integer selected from 0-2, r, s, t are each independently selected from an integer from 0-4, p and q are each independently 0 or 1; and s+q≤4, r+p≤4.

9. The stacked organic electroluminescent device according to claim 8, characterized in that: The Ar 4 ,Ar 5 Each occurrence is independently selected from any one of the following substituted or unsubstituted groups: Wherein, -* represents the attachment site of the group; Preferably, the Ar 4 and Ar 5 No connection or connection via a single key; and / or, The Ar S Each occurrence is independently selected from any one of a single bond and a C6-C20 arylene group, and a single bond or a phenylene group is more preferred.

10. The stacked organic electroluminescent device according to claim 8 or 9, characterized in that: When the total number of light-emitting subunits in the first light-emitting unit and the second light-emitting unit is 2a+1, they are arranged in sequence according to the setting order, and the electron blocking layer material of the a+1th light-emitting subunit has a structure as shown in Formula I or Formula II, preferably has a structure as shown in Formula I; wherein a is an integer ≥1.

11. The stacked organic electroluminescent device according to claim 1, characterized in that: The thickness of the electron blocking layer in at least one of the A-type light-emitting subunits and / or at least one of the B-type light-emitting subunits is independently 4-10 nm, preferably 4-6 nm.

12. The stacked organic electroluminescent device according to claim 1, characterized in that: The glass transition temperature of the electron blocking layer material of at least one light-emitting sub-unit in the first light-emitting unit and the second light-emitting unit is ≥130°C.

13. The stacked organic electroluminescent device according to claim 1, characterized in that: At least one of the A-type light-emitting subunits and / or at least one of the B-type light-emitting subunits are independently selected from any one of a blue light-emitting subunit, a red light-emitting subunit or a green light-emitting subunit.

14. The stacked organic electroluminescent device according to claim 1, characterized in that: A charge generation layer is arranged between any two adjacent light-emitting sub-units.

15. A display device, characterized in that: The display device comprises the stacked organic electroluminescent device according to any one of claims 1 to 14.

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